The crystal display panel has been widely used as the displayer in electronic devices. In a Gate Driver On Array (GOA) circuit, the gate driving circuit for the column scan is configured on an array substrate by using the process of the Thin Film Transistor (TFT) crystal displayer array. In this manner, TFTs of pixels of the crystal display panel can be driven on column by column, which can decrease the production cost and the border of the crystal display panel can be narrowed.
According to the type of TFTs used in the display panel, the display panel produced by using the Low Temperature Poly-Silicon (LTPS) technology includes the NMOS-type display panel, the PMOS-type display panel, and the CMOS-type display panel. Compared with the CMOS-type display panel, the phosphorus doping (i.e., the P doping) is not necessary for producing the NMOS-type display panel. Thus, the NMOS-type display panel has a lower cost and a better yield rate, which makes the NMOS-type display panel be much required in the market.
Currently, large size crystal display panel becomes the mainstream in the market. The load of the GOA circuit increases because the panel size is larger and more columns of pixels are driven. To bare the load, the TFTs size and the border of the panel both increase. As a result, the narrow border crystal display panel can be realized and the GOA circuit has more power loss.
In addition, when the power supply of the crystal display panel is abnormally cur off, if the “All Gate ON” cannot be realized in the GOA circuit (“All Gate ON” is to set all gate driving signals of the GOA circuit as “effective”, and to do a scan for the crystal display panel simultaneously), there will be afterimages shown on crystal display panel.